Magnetic foreign body injuries: a large pediatric hospital experience.

Objective: To examine trends in magnet-related injuries and hypothesize that changes are a result of new neodymium-iron-boron magnets that are smaller, stronger, and commonly sold in sets.

Study Design: In this retrospective chart review, we searched our institution's electronic patient record for patients less than 18 years old who were diagnosed with magnetic foreign body ingestion between 2002 and 2012. Cases were analyzed for patient, magnetic foreign body, and management characteristics.

Classification and regression trees for epidemiologic research: an air pollution example.

Background: Identifying and characterizing how mixtures of exposures are associated with health endpoints is challenging. We demonstrate how classification and regression trees can be used to generate hypotheses regarding joint effects from exposure mixtures.

Methods: We illustrate the approach by investigating the joint effects of CO, NO2, O3, and PM2.

Ciguatera fish poisoning and climate change: analysis of National Poison Center Data in the United States, 2001-2011.

Background: Warm sea surface temperatures (SSTs) are positively related to incidence of ciguatera fish poisoning (CFP). Increased severe storm frequency may create more habitat for ciguatoxic organisms. Although climate change could expand the endemic range of CFP, the relationship between CFP incidence and specific environmental conditions is unknown.

Large, expansile odontogenic cyst with bilateral maxillary sinus involvement.

Residual cysts are common odontogenic lesions of the tooth-bearing areas of the jaws. A case of an unusually large residual cyst that crosses the maxillary midline and occupies portions of the maxillary sinuses is being reported. Investigations included a panoramic radiograph, CT scan and a biopsy.

Inflammatory response after neonatal cardiac surgery and its relationship to clinical outcomes.

Background: Cardiac surgery in infants results in a profound inflammatory response secondary to cardiopulmonary bypass (CPB) and the need for blood products. It is not clear how this inflammatory response modulates postoperative course or whether quantification of proinflammatory cytokines can aid with risk stratification. In this study, we prospectively assessed a panel of candidate markers to determine the time course for inflammation and the association of specific markers with clinical outcomes defined as intensive care unit length of stay (LOS).

Trophic cascade alters ecosystem carbon exchange.

Trophic cascades--the indirect effects of carnivores on plants mediated by herbivores--are common across ecosystems, but their influence on biogeochemical cycles, particularly the terrestrial carbon cycle, are largely unexplored. Here, using a (13)C pulse-chase experiment, we demonstrate how trophic structure influences ecosystem carbon dynamics in a meadow system. By manipulating the presence of herbivores and predators, we show that even without an initial change in total plant or herbivore biomass, the cascading effects of predators in this system begin to affect carbon cycling through enhanced carbon fixation by plants.

Using a depth-sensing infrared camera system to access and manipulate medical imaging from within the sterile operating field.

Background: As surgical procedures become increasingly dependent on equipment and imaging, the need for sterile members of the surgical team to have unimpeded access to the nonsterile technology in their operating room (OR) is of growing importance. To our knowledge, our team is the first to use an inexpensive infrared depthsensing camera (a component of the Microsoft Kinect) and software developed inhouse to give surgeons a touchless, gestural interface with which to navigate their picture archiving and communication systems intraoperatively.

Methods: The system was designed and developed with feedback from surgeons and OR personnel and with consideration of the principles of aseptic technique and gestural controls in mind.

Large, expansile odontogenic cyst with bilateral maxillary sinus involvement.

Residual cysts are common odontogenic lesions of the tooth-bearing areas of the jaws. A case of an unusually large residual cyst that crosses the maxillary midline and occupies portions of the maxillary sinuses is being reported. Investigations included a panoramic radiograph, CT scan and a biopsy.

Impact of time to maternal interview on interview responses in the National Birth Defects Prevention Study.

Prenatal exposures often are assessed using retrospective interviews. Time from exposure to interview may influence data accuracy. We investigated the association of time to interview (TTI) with aspects of interview responses in the National Birth Defects Prevention Study, a population-based case-control study of birth defects in 10 US states.

Characterization of Ambient Air Pollution Measurement Error in a Time-Series Health Study using a Geostatistical Simulation Approach.

In recent years, geostatistical modeling has been used to inform air pollution health studies. In this study, distributions of daily ambient concentrations were modeled over space and time for 12 air pollutants. Simulated pollutant fields were produced for a 6-year time period over the 20-county metropolitan Atlanta area using the Stanford Geostatistical Modeling Software (SGeMS).

Effects of ambient air pollution measurement error on health effect estimates in time-series studies: a simulation-based analysis.

In this study, we investigated bias caused by spatial variability and spatial heterogeneity in outdoor air-pollutant concentrations, instrument imprecision, and choice of daily pollutant metric on risk ratio (RR) estimates obtained from a Poisson time-series analysis. Daily concentrations for 12 pollutants were simulated for Atlanta, Georgia, at 5 km resolution during a 6-year period. Viewing these as being representative of the true concentrations, a population-level pollutant health effect (RR) was specified, and daily counts of health events were simulated.

Linking predation risk, herbivore physiological stress and microbial decomposition of plant litter.

The quantity and quality of detritus entering the soil determines the rate of decomposition by microbial communities as well as recycle rates of nitrogen (N) and carbon (C) sequestration. Plant litter comprises the majority of detritus, and so it is assumed that decomposition is only marginally influenced by biomass inputs from animals such as herbivores and carnivores. However, carnivores may influence microbial decomposition of plant litter via a chain of interactions in which predation risk alters the physiology of their herbivore prey that in turn alters soil microbial functioning when the herbivore carcasses are decomposed.

Sensitivity analysis of a cemented hip stem to implant position and cement mantle thickness.

Patient-specific finite element models of the implanted proximal femur can be built from pre-operative computed tomography scans and post-operative X-rays. However, estimating three-dimensional positioning from two-dimensional radiographs introduces uncertainty in the implant position. Further, accurately measuring the thin cement mantle and the degree of cement-bone interdigitation from imaging data is challenging.

Maternal exposure to particulate air pollution and term birth weight: a multi-country evaluation of effect and heterogeneity.

Background: A growing body of evidence has associated maternal exposure to air pollution with adverse effects on fetal growth; however, the existing literature is inconsistent.

Objectives: We aimed to quantify the association between maternal exposure to particulate air pollution and term birth weight and low birth weight (LBW) across 14 centers from 9 countries, and to explore the influence of site characteristics and exposure assessment methods on between-center heterogeneity in this association.

Methods: Using a common analytical protocol, International Collaboration on Air Pollution and Pregnancy Outcomes (ICAPPO) centers generated effect estimates for term LBW and continuous birth weight associated with PM(10) and PM(2.

Relationship between resource utilization and length of stay following tetralogy of Fallot repair.

Background: The relationship between resource utilization and postoperative length of stay (PLOS) following congenital heart disease surgery is unknown.

Methods: We performed a retrospective cohort study using data from the Pediatric Health Information Systems database. We included subjects 1 month to 1 year of age with a PLOS of ≤ 1 month following elective, complete repair of tetralogy of Fallot (TOF) during 2004-2008 at children's hospitals that performed ≥ 10 such surgeries during the study period.

An exon splice enhancer primes IGF2:IGF2R binding site structure and function evolution.

Placental development and genomic imprinting coevolved with parental conflict over resource distribution to mammalian offspring. The imprinted genes IGF2 and IGF2R code for the growth promoter insulin-like growth factor 2 (IGF2) and its inhibitor, mannose 6-phosphate (M6P)/IGF2 receptor (IGF2R), respectively. M6P/IGF2R of birds and fish do not recognize IGF2.

Cancer vulnerabilities unveiled by genomic loss.

Due to genome instability, most cancers exhibit loss of regions containing tumor suppressor genes and collateral loss of other genes. To identify cancer-specific vulnerabilities that are the result of copy number losses, we performed integrated analyses of genome-wide copy number and RNAi profiles and identified 56 genes for which gene suppression specifically inhibited the proliferation of cells harboring partial copy number loss of that gene. These CYCLOPS (copy number alterations yielding cancer liabilities owing to partial loss) genes are enriched for spliceosome, proteasome, and ribosome components.

Fear of predation slows plant-litter decomposition.

Aboveground consumers are believed to affect ecosystem functioning by regulating the quantity and quality of plant litter entering the soil. We uncovered a pathway whereby terrestrial predators regulate ecosystem processes via indirect control over soil community function. Grasshopper herbivores stressed by spider predators have a higher body carbon-to-nitrogen ratio than do grasshoppers raised without spiders.

Spatial health effects analysis with uncertain residential locations.

Spatial epidemiology has benefited greatly from advances in geographic information system technology, which permits extensive study of associations between various health responses and a wide array of socio-economic and environmental factors. However, many spatial epidemiological datasets have missing values for a substantial proportion of spatial variables, such as the census tract of residence of study participants. The standard approach is to discard these observations and analyze only complete observations.

In vitro evaluation of the Spectra early caries detection system.

Objective: The goal of this study was to perform an in vitro evaluation of the Spectra, a new caries detector that uses light-induced fluorescence of healthy tooth structure and bacterial pigments to optically detect caries. The Spectra generates a storable color map image of examined tooth surfaces which shows areas of enamel and dentin caries. In this study, Spectra readings of occlusal surfaces were compared to clinical, radiographic, and histological assessments of caries.

Thermal Υ(1s) and χb1 Suppression at √(s(NN))=2.76 TeV Pb-Pb collisions at the LHC.

I compute the thermal suppression of the Υ(1s) and χ(b1) states in √s(NN) = 2.76 TeV Pb-Pb collisions. Using the suppression of each of these states I estimate the total R(AA) for the Υ(1s) state as a function of centrality, rapidity, and transverse momentum.

A method to detect residual confounding in spatial and other observational studies.

Background: Residual confounding is challenging to detect. Recently, we described a method for detecting confounding and justified it primarily for time-series studies. The method depends on an indicator with 2 key characteristics: (1) it is conditionally independent (given measured exposures and covariates) of the outcome, in the absence of confounding, misspecification, and measurement errors; and (2) like the exposure, it is associated with confounders, possibly unmeasured.